Systematic Reviews
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Psychiatr. Dec 19, 2021; 11(12): 1366-1386
Published online Dec 19, 2021. doi: 10.5498/wjp.v11.i12.1366
Autism spectrum disorder and personality disorders: Comorbidity and differential diagnosis
Camilla Rinaldi, Margherita Attanasio, Marco Valenti, Monica Mazza, Roberto Keller
Camilla Rinaldi, Roberto Keller, Adult Autism Center, Department of Mental Health, ASL Città di Torino, Turin 10138, Italy
Margherita Attanasio, Marco Valenti, Monica Mazza, Department of Applied Clinical Sciences and Biotechnology, University of L’Aquila, L’Aquila 67100, Italy
Margherita Attanasio, Marco Valenti, Monica Mazza, Regional Centre for Autism, Abruzzo Region Health System, L’Aquila 67100, Italy
Author contributions: Rinaldi C wrote the paper and collected and interpreted the data; Attanasio M incorporated changes during the course of review and edited the paper; Valenti M and Mazza M reviewed and critically revised the paper; Keller R conceived, supervised and reviewed the study and finalized the manuscript. All authors read and approved the final manuscript.
Conflict-of-interest statement: The authors declare no conflict of interests for this article.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Roberto Keller, MD, Chief Doctor, Adult Autism Center, Department of Mental Health, ASL Città di Torino, Local Health Unit, Cso Francia 73, Turin 10138, Italy. rokel2003@libero.it
Received: February 17, 2021
Peer-review started: February 17, 2021
First decision: May 13, 2021
Revised: May 26, 2021
Accepted: November 24, 2021
Article in press: November 24, 2021
Published online: December 19, 2021
ARTICLE HIGHLIGHTS
Research background

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by persistent deficits in social communication and social interaction, as well as restricted, repetitive and stereotyped patterns of behaviour. Individuals with high-functioning ASD are more likely to be diagnosed in adulthood, probably due to the development of learnt or camouflaging strategies that make it much harder to identify the underlying difficulties. Late-diagnosed individuals report higher levels of co-occurring psychiatric disorders or misdiagnosis, because some features of ASD can overlap with symptoms of other psychiatric conditions as well as personality disorders (PD). In recent years there has been a growing interest in exploring the complex relationship between ASD and PD, especially for features that overlap with cluster A and cluster C PD.

Research motivation

Consideration of the relationship between PD and ASD, with a focus on differential diagnosis and comorbidity, can lead to a better understanding of this complex topic and can improve the diagnostic process as well as supporting the creation of targeted interventions.

Research objectives

To summarize the research findings on ASD and PD in adulthood, focusing on comorbidity and differential diagnosis.

Research methods

The guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) were followed in the present review. A comprehensive literature search was performed through PubMed, including only studies published in the English language and performed on adults without intellectual disability. The research included studies published up to April 2020.

Research results

The current review provides a literature summary of how personality and PD have been studied in high-functioning adults with ASD. The findings show that approximately 50% of individuals with ASD fulfilled the diagnostic criteria for at least one PD. The most common comorbid PD belong to cluster A or cluster C (schizoid, schizotypal, obsessive–compulsive and avoidance PD). High-functioning ASD patients are frequently misdiagnosed with PD, but only a few studies have been conducted on differential diagnosis. Furthermore, there were significant differences in methodological approaches, including ASD diagnostic instruments and personality measures.

Research conclusions

ASD in high-functioning adults is associated with a distinct personality profile even if variability exists. Cluster A and cluster C PD are the most frequent co-occurring PD, but overlapping features should be considered. Exploring personality could provide greater understanding of adults with ASD by identifying strengths and weaknesses, and could give relevant information for the development of specific and individual treatments.

Research perspectives

Further studies are needed to explore the relationship between ASD and PD, especially on differential diagnosis. It would be useful to explore the relationship between PD and ASD from a longitudinal perspective, take in account individual’s life and development history.